After the sharpening procedure is complete, run an oil stone lightly along the outside of the teeth once on both sides. This will remove any burr created by the filing.
NOTE: Cross-cut saws only 45º to 70º Soft to hard timber Point file towards handle File cuts on push stroke File one side of alternate teeth until half flat tops are removed STEP 1
NOTE: Shallow end is used for dovetail and tenon saws
Re-position saw in vice to support area being filed
STEP 2 Same angle Saw reversed in vice
Point file towards handle File kept level on push stroke
CARPENTRY - HOUSING
COMMON TIMBER JOINTS HOUSING JOINTS
Housing joints are used in general construction, joinery and cabinetmaking. The most common types include through, stopped and side housings but there are others, which are used for specific purposes. These include the shouldered, dovetailed and end lap housings.
Shouldered housing
A shoulder is formed on the end of the horizontal member so that the length of all pieces will all be cut exactly to the shoulder length. The depth of the housing or the length of the tongue is not as important as the shoulder to shoulder length. It may be used to construct book cases or built-in shelving.
Fig. 46 Shouldered housing
Half dovetail housing
This type of joint is used where strength is important and it is not desirable to fix with screws or nails, for appearance reasons. Once glued and cramped this joint is very suitable for exposed sided cabinet or shelving work, although time consuming to prepare.
Fig. 47 Half dovetail housing
BUILDING MATERIALS and HAND TOOLS
End lap housing
This joint is typically used for the construction of boxes, trays, carry-alls, etc. where the joint is to be glued and nailed or screwed. Where additional strength is required and appearance is important, a lapped dovetail joint may be used instead of the end lap joint.
Fig. 48 End or corner lap housing
SET OUT AND CONSTRUCTION OF THE JOINTS
A similar process is involved in setting out all housing joints. The following steps may be applied to any of the above joints with only a slight variation for each individual joint.
Construction of a Through Housing joint
Fig. 49 Setting out the joint
STEP 1. Select and mark the face side and edge on each piece.
Mark the position and width of the housing on one piece, using the end of the other piece as the template, on the opposite side to the face mark.
Square these marks across the width of the timber and down both edges.
Use other piece to mark thickness Face mark
Edge mark
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Fig. 50 Gauging depth of housing
Fig. 51 Cutting on the waste side of the line
STEP 2. Mark the depth of the housing on one edge.
Set a marking gauge to the depth mark from the face side and gauge a line on both edges.
Place a cross or other suitable mark on the waste area to be removed so that the waste side cannot be mistaken.
Note: The gauge is always set from the face side so that any subsequent joints will have the same amount left on if the timber used happens to vary slightly in thickness. This ensures that the overall frame will remain parallel throughout its length.
STEP 3. Using a crosscut saw, cut along the face side marks, on the waste side, to the depth marked on the edges. To allow easy removal of the waste an additional relief cut may be made in the centre of the housing. More than one relief cut may be necessary on wide housings.
Hint: A temporary timber fence may be cramped to the edge of the cutting lines, on the side which remains, to ensure a straight saw cut along the line.
Marking gauge
Gauge line
Place 'x' on waste section
Saw cuts on waste side of lines
Relief cut Cross cut saw
BUILDING MATERIALS and HAND TOOLS
Fig. 52 Tap the chisel along the depth marks
Fig 53 Chisel out small sections of waste
Fig. 54 Pare the bottom of the housing smooth and straight
STEP 4. Remove the waste with a sharp wide chisel. Firstly, tap the chisel lightly along the depth marks on both edges. This will prevent any splitting out below the depth marks when chiselling out the waste. Secondly, chisel out small sections of waste working from both edges. This will prevent large chunks being torn out which create hollows in the housing.Thirdly, pare the base of the housing to form a smooth, flat surface. Alternatively, a hand router may be used to provide a flat straight surface, especially for joinery work.
Place chisel edge on waste side of line before tapping
Chisel approximately 1/3 of the waste each time
Use a broad sharp chisel
CARPENTRY - HOUSING
VARIOUS TYPES OF HOUSINGS
Fig. 55 Housing joints THROUGH HOUSING
STOPPED HOUSING
ANGLE HOUSING
BEVEL HOUSING
BUILDING MATERIALS and HAND TOOLS
Mortise and Tenon Joints
This is the most common type of framing joint used for joinery doors, panelled doors, timber window sashes, etc. The joint consists of a thin section on one end of a piece of timber called the ‘tenon’ and a slot in another piece of timber, which is the same thickness as the tenon, called the ‘mortise’. When the two are glued and fitted together the joint has two wedges driven into either side of the tenon to provide a locking action. The joint may also be pinned through the face instead of fitting wedges.
Common or Through Mortise and Tenon
This joint is normally used where a rail meets a stile and there is at least a small section of stile on either side of the joint. The rail will have a tenon cut on the end, which is equal to the full width of the rail, and a thickness equal to one third of the rail thickness, or the nearest chisel size. The stile will have a mortise which is complimentary in size to the tenon on the rail. The outside edge of the mortise will have a wedge allowance cut on either side to allow the tenon to be locked in when the joint is assembled.
Fig. 56 Common mortise and tenon joint
Fig. 57 Pinned or Foxwedged stub mortise and tenon joints Tenon
Wedges Mortise
Wedge allowance
Shoulder
Wedges inserted into saw cuts
CARPENTRY - HOUSING
Single Haunched mortise and Tenon
This joint is used at the end of a stile where there is no timber on one side of the joint. The haunch or cut away tenon remains concealed. If the tenon is exposed at the end then the joint becomes known as a 'bridle’ joint.
Fig. 58 Haunched mortise and tenon
Barefaced Mortise and Tenon
This joint is used where the rail is thinner than the stile and the mortise is required to be kept close to centre. The tenon only has one shoulder and is kept flush with one edge.
Fig. 59 Barefaced mortise and tenon
Square haunch
Bevelled haunch
Barefaced tenon
BUILDING MATERIALS and HAND TOOLS
Double Haunched Mortise and Tenon
This consists of two haunched tenons cut on the end of a wide rail, which is to be fitted to a stile. The double tenon prevents the wide rail from twisting at the joint. These joints are commonly used for the bottom rail to stile connection on a framed door.
Fig. 60 Double haunched mortise and tenon
SET OUT AND CONSTRUCTION OF THE JOINTS
A similar process is involved in setting out all mortise and tenon joints. The following steps may be applied to any of the above joints with only a slight variation for each individual joint:
Construction of a Common Mortise and Tenon
Fig. 61 Setting out the stile including wedge allowance
STEP 1. Select and mark the face side and edge on each piece.
Mark the position and width of the mortise on one edge of the stile, using the end of the rail as the template, and square these marks around to the opposite edge.
Add a wedge allowance on the outside of the stile, which should be equal to a slope of 1:12. Set out the length of the tenon to be equal to the width of the stile plus approx. 2mm waste.
Double tenon
Double haunch
Set out wedge allowance
W.A.
Set out the width of the mortise
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Fig. 62 Gauge the edges of the stile
Fig. 63 Chisel out the waste and create wedge allowance
STEP 2. Select a chisel which will be used to cut the mortise. It should be equal to or close to one third of the stile thickness.
Set the two marking spurs of the mortise gauge to suit the width of the selected chisel and set the stock to suit the distance from the face side of the stile to the first edge of the mortise.
Gauge double lines on both edges of the stile ready to be chiselled out.
At the same time, use the same gauge set up to gauge the tenon on the end of the rail, also from the face side. Mark the two sides and the end of the rail.
STEP 3. Clamp the stile to a chiselling block and start chiselling small chunks out of the mortise on one side, starting at the centre and working towards one end.
Chisel part of the way through from one side, then turn the stile over and repeat the operation from the other side until the chisel breaks through.
Chisel out the waste on either end of the mortise to form the wedge allowance, on one edge of the stile only.
Setting the gauge to suit the chisel
Gauge from face side
Gauging the tenon
Gauging the mortise
Chisel from the centre of the mortise towards the ends
BUILDING MATERIALS and HAND TOOLS
ALTERNATIVE METHOD OF REMOVING WASTE FROM THE MORTISE
Fig. 64 Machine mortising
Chisel bush Fit into auger bush
Fit into chisel bush
Direction of Special auger has a chip breaking action a) Initial adjustment
b) Operational travel
BASIC MACHINE MORTICING
NOTES: Select a drilling speed to suit the hollow mortise chisel size. Higher speeds for small chisels, lower speeds for large chisels.
Place the face side of the material against the fence.
Mortice half way through the material then turn over and mortice out the remaining waste material
Higher clearance hole to other side or rear
Allow a slight projection of the auger to provide bite into the timber and prevention of friction burning to the end of the hollow bit.
ADJUSTMENT OF AUGER
HOLLOW MORTISE CHISEL AND AUGER Available in deep hole
and stub lengths b) a)
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Fig. 65 Rip the cheeks of the tenon
Fig. 66 Cut the shoulders of the tenon and clean up
STEP 4. Place the rail in the vice on an angle so the marks for the tenon are visible on the edge and the end.
Use a tenon saw to rip along the marks which form the cheeks on the edge and end.
Turn the rail over and repeat the process.
Turn the rail to a vertical position in the vice and cut square across on both sides of the tenon down to the shoulder lines.
STEP 5. Place the rail on a bench hook and cut across the shoulder line down to the tenon.
Turn the rail over and repeat the process for the other side.
Pare the tenon with a wide sharp chisel to remove any remaining waste.
Ripping tenon cheeks on the waste side
Cutting the tenon shoulders on the waste side
BUILDING MATERIALS and HAND TOOLS
Fig. 67 Fit, glue, cramp and wedge the joint
Fig 68 Dress the joint
STEP 6. Fit the joint together, dry, and prepare the wedges. The joint should be a hand tight fit which may be pulled apart without excessive force.
Apply adhesive, such as PVA, to the joint surfaces and press together.
Cramp the joint tightly, square up if a frame is formed, apply some adhesive and drive in the wedges.
STEP 7. When the adhesive has set, remove the job from the cramps, place it in the vice and plane the protruding tenon and wedge ends flush.
Wedge
Wedge driven in to lock the tenon
FINISHED JOINT Finished joint planed
flush on end
CARPENTRY - HOUSING
Dowelled Joints
Dowelled joints used in joinery give good results. They are prepared by boring holes in adjacent pieces of timber to be joined. The pieces are then connected by the dowels, cylindrical wooden pins, which are glued into the corresponding holes.
As less labour is required in making dowelled joints they are cheaper to prepare. Less timber is needed, as no provision for a tenon is required, therefore a considerable saving is made when the stiles and rails are of large section sizes.
Setting out
The strength of framing joints depends mainly on their rigidity, which is ensured by maintaining pressure at the shoulders. The number and spacing of the dowels is therefore critical.
The number of dowels required will depend on the width of the timber. One dowel would allow the rail to pivot or cup, therefore a minimum of two are required. If the dowels are too far apart the rail may still cup and if too close together it could lead to splitting of the rail.
As a good practical rule:
• allow one dowel for every 40mm of rail end width and not closer than 12mm to an edge.
• allow one dowel for every 150mm of length when joining timber at the long edge.
The diameter of the dowels should be as near as possible to one third the thickness of the rail but not more than half the rail.
Jigs
When setting out several jobs, templates can be used to advantage. These may consist of timber or metal with small holes corresponding to the positions of the dowels. The dowel positions are marked by pricking through with a nail or scriber. The use of a template ensures accuracy in setting out and matching the holes for the dowels.
There are situations when conventional methods for setting out are not practical or easy. In this situation a ‘spec’ may be used, which is the trade name given to a small metal plug with a point at the axis of one end. The diameter of the plug should be a snug fit in the dowel hole with the shoulder of the spec preventing it from disappearing down the hole.
In cases where specs are used, holes are bored in one member, the specs are placed into the holes, the member to be joined is placed beside the bored member and tapped against the specs. This marks the centre of the holes to match those already bored.
Fig. 69 Jigs for marking centres
METAL ANGLE
DOWEL SPEC OR POP TRY SQUARE AND PENCIL SPEC STICK
BUILDING MATERIALS and HAND TOOLS
Boring Holes
Holes may be bored using a clamp jig and a portable electric or battery drill. The detail below outlines the use of the jig and identifies the parts.
Fig. 70 Dowelling jig
Item Part or Function
1 Depth stop
2 Thumb screw or set screw
3 Clamp screw (approx. 75mm capacity) 4 Centering gauge marks
5 Interchangeable guide collars (six sizes supplied) 6 Sliding cradle for guide collars
7 Centering notch
8 Wing nut for adjustment of sliding cradle Use of dowelling jig. An electrical drill or a brace and bit
are used with a depth gauge for drilling dowel holes.
CARPENTRY - HOUSING
Holes may also be bored using a horizontal boring machine or a vertical drill press.
Consistent size, depth and position is maintained by using these machines.
Fig. 71 Typical horizontal boring machine
Drill Bits
A standard twist bit may be used with the clamping jig , but a dowelling centre bit is preferred when using horizontal borers or drill presses to ensure the bit does not wander from the hole centre, when the hole is started.
Countersink bits are used to ‘flare’ the top of the holes for the dowels so the excess glue has somewhere to go when the joint is pressed together, as hydraulic pressure may prevent the joint being pressed tightly together.
Fig. 72 Commonly used bits for dowelling
Item Part or Function
A Motor
B Chuck
C Sliding table D Depth stop E Locking screw F Height adjustment
G Switch
DOWEL DRESSING BIT COUNTERSINK BIT
STANDARD TWIST BIT
CENTERING BIT
COUNTERBORE BIT G
F E D C B A
BUILDING MATERIALS and HAND TOOLS
Gluing
Bored holes for the dowels only provide minimum clearance therefore the film of glue placed on the surfaces to be bonded is not applied the same as for other closed face joints.
When the glue is placed in the holes and the dowels are driven in pressure from the trapped air will prevent complete insertion or it will burst the timber.
Fig. 73 Result of incorrect and correct preparation
To prevent this occurring, the dowels may have a slot cut along one or more edges, have one side planed flat or be multi-grooved:
Fig. 74 Prepared dowels
Clearance
Dowel holes are drilled to a depth so that the combined length of the two holes is 2 to 3mm greater than the length of the dowel. It will also be noted that the dowel is chamfered at both ends to help guide them into their holes.
Length
In narrow members, the dowel should e one and one third times the width of the stile, e.g. if the stile is 60mm finished size then the dowel should be 80mm long. This means 40mm into each side of the joint.
MULTI-GROOVED SINGLE GROOVED FLAT PLANED
CARPENTRY - HOUSING
TIMBER SURFACE PREPARATION Abrasive Papers
An abrasive paper is one which has a surface coated with abrasive bonded to a flexible backing for the purpose of abrading materials, to remove marks and prepare the surface for finishing.
Manufacture
Grits for use as an abrasive are graded in various particle sizes, after the stone or manufactured material has been crushed. Grits in use for general work range from size 12, very coarse, to size 320, very fine. Some grits used for other industrial purposes may be as fine as size 600.
The grading figure indicates the number of particles, if placed in a line, to cover a lineal measurement of 25mm. The abrasive is stuck to the backing by means of a suitable adhesive. High quality animal glues and synthetic resins are used for this purpose. Abrasive papers may be open coated or close coated. Open coated paper has 30% to 50% of its area without grit, while closed coated paper has the abrasive grain covering the entire paper surface.
Open coated papers have the advantage of higher flexibility and are less likely to clog during use.
Definitions
Glue bond - a glue bonded product employs an animal hide glue bonding system where
Glue bond - a glue bonded product employs an animal hide glue bonding system where